Game system, game management method, and game management program

ABSTRACT

This game system has an allocation unit ( 3612 ) for allocating players, who wish to participate in a versus game, to a game space, a log acquisition processing unit ( 3614 ) for storing, as log information, other players who played in the same game space every time the game ends, fraud determination means ( 3613 ) for performing first fraud determination processing of registering in a partnering prohibition list a team of two players determined to be suspected fraud players based on the log information, and second fraud determination processing of registering teams of a fraud player and each of the other players allocated to the same game space in the partnering prohibition list based on the log information, and a restriction unit ( 3617 ) for restricting the allocation of a team of suspected fraud players registered in the partnering prohibition list to the same game space. Whereby, the allocation of collaborators who are suspected of committing fraud to the same game space can be prevented.

TECHNICAL FIELD

The present invention relates to a game system, a game management method and a game management program which manage the fraudulent acts of players playing a network game.

BACKGROUND ART

In recent years, the game scores of players that played a game with the game terminal device are being collected in a host via a network, and the nationwide ranking of players is being calculated based on the cumulative game scores of the respective players. The ranking is updated at game end, and is immediately distributed to the game device and displayed on a monitor. The ranking is higher as the game score is higher. The players try to achieve better game scores in order to increase their ranking as much as possible.

Meanwhile, in a game such as a mahjong game that is played via a network, the opponents are generally decided according to the order of entry. Here, if two players make an entry at the same time in collusion, it is likely that they will be allocated to the same table (same game space). In addition, if the two players advance the mahjong game in collusion with one player playing the role of a winner and the other player playing the role of a loser, it is possible to realize an inappropriate behavior of allowing the player playing the role of a winner to achieve a high score (for example, first place). Such behavior is unrelated to the actual skills of that player, and deceives the remaining legitimate members. Since there will be unjustness in the ranking in relation to the other players, measures need to be taken in order to prevent this kind of fraudulent act.

Patent Document 1 describes a method of recording entrants who won in a match that was played with the same team, and, in subsequent groupings, grouping the respective entrants so that they will not be in the same team as the entrants who have won against oneself in the past. It is thereby possible to reduce the possibility of a malicious entrant from continuously playing the match in collaboration with the same entrant, and provide a game that can be played under fair conditions.

-   Patent Document 1: Japanese Patent Application Publication No.     2004-113743

Incidentally, the fraudulent act prevention method described in Patent Document 1 groups the respective entrants so that they will not be in the same team as the players who won a match with the same team in the past for each entry to the game, and thereby eliminates the possibility of fraud opportunities. Accordingly, for example, in a mahjong game, players who were first place and second place or players who were third place and fourth place in a previous game are also prevented from being grouped in the same team in the future, and there is a possibility that the two-player team, which will not necessarily commit fraud, will also be separated with the determination method that only focuses on players who have won against oneself. Moreover, the number of players who have won against oneself in a game; that is, the number of relative winners and losers will be numerous for each game and when considering the number of games that is played daily, and a drawback where mutual opponents are suddenly narrowed may arise. Accordingly, even if attention is focused on the win/loss of the game, there is a problem in effectively eliminating the team of players with a malicious intent.

SUMMARY OF THE INVENTION

The present invention was devised in view of the foregoing problems, and its object is to provide a game system, a game management method and a game management program capable of effectively inhibiting fraudulent acts by not allocating collaborators who are suspected of committing fraud to the same game space with an immediate effect, and extracting the suspected fraud player to play the role of the winner and not allocating that player and the suspected fraud collaborator to the same game space with a delayed effect.

The present invention is a game system comprising respective game terminals which allow a plurality of players to play a versus game in a same game space via a network, and a game server which is provided on the network and which manages the players who participate in the versus game, wherein the game terminal has acceptance means for accepting entries to the versus game, and the game server has: allocation means for allocating players, whose entry has been accepted, to the game space according to predetermined rules; log storage means for storing, as log information, game scores of the respective players, and other players who played a versus game in a same game space every time the game ends; fraud determination means for performing first fraud determination processing of determining, based on a record of allocation to the same game space of a team of two players who have been allocated to the same game space which is obtained from the log information, whether those two players are suspected fraud players committing joint discard, and registering in a partnering prohibition list the team of the two players when those two players are determined to be suspected fraud players, and second fraud determination processing of determining, based on a record of allocation to the same game space of each player in relation to a plurality of other players which is obtained from the log information, whether that player is a suspected fraud player committing joint discard, and registering in the partnering prohibition list teams of that fraud player and each of the other players allocated to the same game space when that player is determined to be a suspected fraud player; and restriction means for restricting the allocation of two players to the same game space when those two players whose entries to the versus game have been accepted are registered as a team of suspected fraud players in the partnering prohibition list.

The present invention is also a game management method of a game server which manages players who play a versus game in a same game space by operating respective game terminals connected to a network, wherein allocation means allocates players, whose entry has been accepted, to the game space according to predetermined rules, log storage means stores, as log information, game scores of the respective players, and other players who have played a versus game in the same game space every time the game ends, fraud determination means performs first fraud determination processing of determining, based on a record of allocation to the same game space of a team of two players who have been allocated to the same game space which is obtained from the log information, whether those two players are suspected fraud players committing joint discard, and registering in a partnering prohibition list the team of the two players when those two players are determined to be suspected fraud players, and second fraud determination processing of determining, based on a record of allocation to the same game space of each player in relation to a plurality of other players which is obtained from the log information, whether that player is a suspected fraud player committing joint discard, and registering in the partnering prohibition list teams of that fraud player and each of the other players allocated to the same game space when that player is determined to be a suspected fraud player, and wherein restriction means restricts the allocation of two players to the same game space when those two players whose entries to the versus game have been accepted are registered as a team of suspected fraud players in the partnering prohibition list.

The present invention is also a game management program of a game server which manages players who play a versus game in a same game space by operating respective game terminals connected to a network, the game management program causing the game server to function as: allocation means for allocating players, whose entry has been accepted, to the game space according to predetermined rules; log storage means for storing, as log information, game scores of the respective players, and other players who have played a versus game in the same game space every time the game ends; fraud determination means for performing first fraud determination processing of determining, based on a record of allocation to the same game space of a team of two players who have been allocated to the same game space which is obtained from the log information, whether those two players are suspected fraud players committing joint discard, and registering in a partnering prohibition list the team of the two players when those two players are determined to be suspected fraud players, and second fraud determination processing of determining, based on a record of allocation to the same game space of each player in relation to a plurality of other players which is obtained from the log information, whether that player is a suspected fraud player committing joint discard, and registering in the partnering prohibition list teams of that fraud player and each of the other players allocated to the same game space when that player is determined to be a suspected fraud player; and

restriction means for restricting the allocation of two players to the same game space when those two players whose entries to the versus game have been accepted are registered as a team of suspected fraud players in the partnering prohibition list.

The present invention is also a game system comprising respective game terminals which allow a plurality of players to play a versus game in a same game space via a network, and a game server which is provided on the network and which manages the players who participate in the versus game, wherein the game terminal has acceptance means for accepting entries to the versus game, and wherein either the game terminal or the game server has: allocation means for allocating players, whose entry has been accepted, to the game space according to predetermined rules; log storage means for storing, as log information, game scores of the respective players, and other players who have played a versus game in the same game space every time the game ends; fraud determination means for performing first fraud determination processing of determining, based on a record of allocation to the same game space of a team of two players who have been allocated to the same game space which is obtained from the log information, whether those two players are suspected fraud players committing joint discard, and registering in a partnering prohibition list the team of the two players when those two players are determined to be suspected fraud players, and second fraud determination processing of determining, based on an allocation record to the same game space of each player in relation to a plurality of other players which is obtained from the log information, whether that player is a suspected fraud player committing joint discard, and registering in the partnering prohibition list teams of that fraud player and each of the other players allocated to the same game space when that player is determined to be a suspected fraud player; and restriction means for restricting the allocation of two players to the same game space when those two players whose entries to the versus game have been accepted are registered as a team of suspected fraud players in the partnering prohibition list.

According to the foregoing inventions, when an entry is accepted by the game terminal, the allocation means allocates the player whose entry was accepted to the game space according to predetermined rules. Every time the game ends, the log storage means stores, as log information, game scores of the respective players, and other players who played in the same game space. In addition, the fraud determination means performs the first fraud determination processing and the second fraud determination processing. Specifically, first fraud determination processing of determining, based on an allocation record to the same game space of a team of two players who were allocated to the same game space which is obtained from the log information, whether those two players are suspected fraud players committing joint discard, and registering the team of the two players in a partnering prohibition list when those two players are determined to be suspected fraud players is performed. Moreover, second fraud determination processing of determining, based on an allocation record to the same game space of each player in relation to a plurality of other players which is obtained from the log information, whether that player is a suspected fraud player committing joint discard, and registering teams of that fraud player and each of the other players allocated to the same game space in the partnering prohibition list when that player is determined to be a suspected fraud player is performed. Upon receiving the results of the foregoing fraud determination, the restriction means restricts or prohibits the allocation of two players to the same game space when those two players whose entries to the versus game were accepted are registered as a team of suspected fraud players in the partnering prohibition list.

Accordingly, the collaborators who are suspected of committing fraud in a game are not allocated to the same game space based on the first fraud determination processing with an immediate effect, and the suspected fraud player to play the role of the winner is extracted and that player and the suspected fraud collaborator are not allocated to the same game space based on the second fraud determination processing with a delayed effect, and fraudulent acts are thereby inhibited effectively. Note that a joint discard is a fraudulent game operation where two players are allocated to the same table and one player plays the role of a loser to allow the other player to win the game. Moreover, as the predetermined rules for allocation, in addition to first come, first served, various methods can be adopted such as giving consideration to differences in attributes, the rules need to at least be related to the acts of the player in relation to the allocation to the same game space. For example, in the case of first come, first served, this refers to the act of simultaneously accepting entries. In the case where differences in attributes are involved, this refers to the act of falsifying data in advance for causing the attributes to coincide. Moreover, an allocation record is a record that gives consideration to the number of times or frequency that the players were allocated to the same game space.

The collaborators who are suspected of committing fraud in a game are not allocated to the same game space with an immediate effect, and the suspected fraud player to play the role of the winner is extracted and that player and the suspected fraud collaborator are not allocated to the same game space with a delayed effect, and fraudulent acts are thereby inhibited effectively.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a configuration diagram showing an embodiment of the game system according to the present invention.

FIG. 2 is a perspective view showing the exterior of one embodiment of the game terminal device.

FIG. 3 is a hardware configuration diagram showing one embodiment of the game terminal device.

FIG. 4 is a functional configuration diagram of the control unit of the game terminal device.

FIG. 5 is a hardware configuration diagram showing one embodiment of the server device.

FIG. 6 is a functional configuration diagram of the control unit of the server device.

FIG. 7 is an example of the screen view of the mahjong game match screen.

FIG. 8 is a flowchart explaining the mahjong game progress processing to be executed by the CPU 361 of the server device 3, and is a flowchart showing the processing in the case of receiving a signal from the game terminal device 1.

FIG. 9 is a flowchart showing the processing in the case where the received signal was an acceptance signal.

FIG. 10 is a flowchart showing the processing in the case where the received signal was game end.

FIG. 11 is a flowchart showing the suspected fraud player extraction processing to be executed every predetermined short period (one day).

FIG. 12 is a flowchart showing the allocation processing.

FIG. 13 is a flowchart showing the allocation processing.

FIG. 14 is a flowchart showing the short-term fraud countermeasure processing.

FIG. 15 is a flowchart showing the long-term fraud countermeasure processing.

FIG. 16 is a flowchart showing the long-term fraud countermeasure processing.

FIG. 17 is a flowchart showing the long-term fraud countermeasure processing.

FIG. 18 is a flowchart showing the long-term fraud countermeasure processing.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a configuration diagram showing an embodiment of the game system according to the present invention. The game system comprises game terminal devices 1 respectively associated with identification information, a router 2 serving as a communication device which is communicably connected to the plurality of (eight in this example) game terminal devices 1, which performs the relay and communication among the game terminal devices 1, and which connects the respective game terminal devices 1 and game terminal devices of other stores via a network (for example, the internet), and a server device 3 communicably connected via the respective routers 2 and which manages information concerning player authentication for a plurality of players to play a game via the game terminal devices 1, selection of player grouping, game scores of the respective players, and ranking of all players. The respective game terminal devices 1 and the router 2 are connected via a LAN (Local Area Network) cable.

The game terminal device 1 comprises a power switch not shown at an appropriate location on its case (for example, on the back face of the case), and is activated by the power being turned ON. The game terminal device 1 is used for advancing the game by receiving game play operations from a player who is playing the game while viewing a game image displayed on a monitor. Note that the identification information that is associated with the game terminal device 1 includes identification information of each router 2 to which the game terminal devices 1 are connected (or identification information of the store where the game terminal devices 1 are installed) and identification information of each game terminal device 1 in the store where the game terminal devices 1 are installed. For example, when the identification information of store A is A and the identification information of the game terminal device 1 in store A is 4, the identification information of that game terminal device 1 is A4.

The router 2 is communicably connected to each of the plurality of game terminal devices 1 and the server device 3, and transfers data between the game terminal devices 1 and the server device 3.

The server device 3 is communicably connected to the respective routers 2, stores information such as the player information by associating it with the user ID as unique information (identification information) for identifying the individual players, and also manages information concerning players (opponents) that are playing the game in the same game place as the player by sending and receiving data to and from the respective game terminal devices 1 via the router 2 through use of the identification information of the game terminal devices 1.

FIG. 2 is a perspective view showing the exterior of one embodiment of the game terminal device 1. Note that the game that is played using the game terminal device 1 may be a personal game or a versus game. This embodiment is assuming a mahjong game (refer to FIG. 7), and the player operating the game terminal device 1 and the players operating the other game terminal devices 1 will play a match. In the match with the players operating the other game terminal devices 1, operational data according to the operations of the respective players is transferred among the game terminal devices 1, which are being used for playing the match, via a network communication unit 18 described later and the router 2.

The game terminal device 1 comprises a monitor 11 for displaying a game screen, a touch panel 11 a laminated on the monitor 11 and which senses the pressing force of the player and determines which button has been pushed based on the address of the button that urges the player to select the options displayed on the game screen of the monitor 11 and the position that was pressed by the player, a speaker 12 for outputting sound, a card reader 13 for reading information such as the user ID that is stored in a personal card, and a coin acceptance unit 14 for accepting the coins that were inserted by the player. The monitor 11 displays a game screen, and is configured from a liquid crystal display, a plasma display or the like.

Moreover, a personal card is a recording medium such as a magnetic card or an IC card which stores personal information such as the user ID. A conventional card reader 13 has been adopted to read the recorded data in a state where the personal card has been inserted into the reading slot not shown, maintain the inserted state while the game is ongoing, and allow the removal of the card with removal means not shown when the game is ended and instructions for removing the card are received from the player. Note that in cases where the personal card is configured to enable close range communication via radio waves or infrared, a reception element capable of sensing radio waves and infrared is adopted as the card loader 13. Moreover, it may also be configured to enable bidirectional communication of required information as needed.

A control unit 16 (refer to FIG. 3) configured from a microcomputer which outputs detected signals from the respective units or control signals to the respective units is disposed at an appropriate location of the game terminal device 1.

FIG. 3 is a hardware configuration diagram showing one embodiment of the game terminal device 1. The control unit 16 controls the overall operation of the game terminal device 1, and comprises an information processing unit (CPU) 161 which performs various types of information processing including acceptance processing, processing concerning the overall progress of the game, image display processing and so on, a RAM 162 for temporarily storing information in the midst of being processed, and a ROM 163 which stores in advance predetermined image information including the game screen, various types of setting information, game programs, and the like.

An external I/O control unit 171 converts detected signals into digital signals for processing between the control unit 16 and the detection units including the card reader 13, the touch panel 11 a (operation unit) and the coin acceptance unit 14, and converts the command information into control signals of the respective devices of the detection units, and outputs such signals. The external I/O control unit 171 performs the foregoing signal processing and I/O processing, for example, based on time division. The external device control unit 172 performs the output operation of control signals to the respective devices of the detection units and the input operation of detected signals from the respective devices of the detection units within their respective time division periods.

A graphic (image drawing) processing unit 111 displays a required screen on the monitor 11 according to the image display command from the control unit 16, and comprises a video RAM and the like. A sound reproduction unit 121 outputs, from the speaker 12, a predetermined message, BGM or the like according to a command from the control unit 16.

The ROM 163 stores various screens in addition tile objects, a table screen, a game screen for the respective buttons, a game entry screen and the like. The tile objects are configured from a required number of polygons so that they can be rendered three-dimensionally, and the graphic processing unit 111 performs calculation and light source calculation processing for converting the position in the three-dimensional space to a position in a simulated three-dimensional space based on a graphic command from the CPU 161, and further performs write processing of image data to be rendered to the video RAM based on the foregoing calculation results; for example, write (paste) processing of texture data to an area of the video RAM that is designated by the polygons.

Here, the relation of the operation of the CPU 161 and the operation of the graphic processing unit 111 is explained. The CPU 161 reads, from the ROM 163, the image, sound and control program data and game program data based on the operating system (OS) that is recorded in the ROM 163 that can be detachably mounted on a built-in or external image display processing unit for outputting and displaying image information to and on the monitor 11. A part or all of the read image, sound and control program data are retained in the RAM 162. Subsequently, the CPU 161 performs processing based on the control program and various data (image data and sound data including polygons and textures of objects to be displayed and other text images) stored in the RAM 162, as well as the detected signals from the detection units.

Data that can be stored in a removable recording medium among the various types of data stored in the ROM 163 may also be readable with drivers of, for example, a hard disk drive, an optical disk drive, a flexible disk drive, a silicon disk drive, a cassette medium reader or the like. In the foregoing case, the recording medium is, for example, a hard disk, an optical disk, a flexible disk, a CD, a DVD, a semiconductor memory or the like.

The network communication unit 18 sends and receives the player's operational information which arises during the execution of the mahjong game to and from the game terminal devices 1, which are being used to play the match, via the router 2 and additionally via the network. In addition, the network communication unit 18 also sends and receives to and from the server 3 information required for the personal authentication during the entry processing of a new player, before and after the execution of the game, and game scores at the end of the game via the router 2.

FIG. 4 is a functional configuration diagram of the control unit 16 of the game terminal device 1. As a result of executing the game programs retained in the RAM 162, the CPU 161 of the control unit 16 functions as an acceptance processing unit 161 a which accepts entries to the game from players, a game progress control unit 161 b which controls the sequential progress of the mahjong game from the start to end of the game, an image display processing unit 161 c which displays an entry image, game image, game end image, ranking display image and the like on the monitor 11, a score processing unit 161 d which decides the game score (value of points of point sticks on hand) and ranking at the end of the game by evaluating the player's operation during the game, a dan grade setting unit 161 e which sets a dan grade as an attribute representing the strength level of that player in the game based on the number of items that are virtually held by that player, a title setting unit 161 f which calculates the parameter representing that player's characteristics in the game based on the history data stored in a history storage unit 162 a described later, and awards a title as an attribute to that player based on the calculated parameter, and a communication control unit 161 g which performs the communication control of the various types of information.

The acceptance processing unit 161 a reads the user ID from the personal card that was inserted into the card reader 13 of the game terminal device 1 after the touch panel 11 a detects that the entry button or the like not shown displayed on the monitor 11 has been pressed by the player wishing to enter the game.

The game progress control unit 161 b allows four players to play a mahjong game as shown in the game screen of FIG. 7, and the order of tsumo (drawing the last tile needed to complete a hand) among the players is repeated in a predetermined order. Moreover, the game progress control unit 161 b allows a player to discard one of its tiles in hand, within a predetermined time, for each occurrence of tsumo. Accordingly, the player will think of which tile should be discarded for each occurrence of tsumo, and perform an operation for designating the decided tile; that is, perform an operation of pressing the display position of the corresponding tile object. When this operation is performed, the communication control unit 161 g sends this operational information to the other game terminal devices 1 of the (same virtual table; that is, same game space) playing the match, and the contents of the screen of the game terminal devices 1 of oneself and other players are updated, and tsumo will occur in the game terminal device 1 to play the next hand.

The score processing unit 161 d determines the ranking in descending order from the most points owned by the player as virtual point sticks when the game is ended. However, at the start of the game, the points (original points) that are owned by the player as virtual point sticks are the same. The original points are, for example, 15000 points in the case of a first round, 20000 points in the case of an East wind match, and 25000 points in the case of a half game. The score processing unit 161 d successively stores the game scores and the like in the game score storage unit 162 b, and the stored contents are sent to the server device 3 by the communication control unit 161 g at the end of each game.

The dan grade setting unit 161 e decides the dan grade (for example, tenth kyu grade to first kyu grade to first dan grade to eighth dan grade) representing the player's strength level in the game based on the number of items that are virtually owned by the player. Note that the items are transferred among other players according to the scores obtained in the score processing unit 161 d in a predetermined quantity among the items that are virtually owned by the respective players. For example, two items are transferred from the fourth ranking player to the first ranking player, and one item is transferred from the third ranking player to the second ranking player for each game.

The title setting unit 161 f virtually awards a title to the player in the game based on the calculated parameters when that player is promoted to the first dan grade in the decision of dan grades performed by the dan grade setting unit 161 e. The parameters include, for example, conventional winning rate, payment rate, average dora count and average han count. The title awarding unit 161 f sets the parameters by referring to the levels of the winning rate, payment rate, average dora count and average han count, and awards the title corresponding to the highest parameter. For example, if the level of the winning rate is the highest, it is determined that the player a hit-and-run type player and is awarded the title of “Vermillion Bird.” If the level of the payment rate is the highest, it is determined that the player is a defensive player and is awarded the title of “Black Tortoise.” If the level of the average dora count is the highest, it is determined that the player depends on luck and is awarded the title of “Azure Dragon.” If the level of the average han count is the highest, it is determined that the player is an offensive player and is awarded the title of “White Tiger.” The respective titles represent the character names that show the type of playing (for example, hit-and-run) that is carried out by that player.

Here, the RAM 162 of the control unit 16 is explained. The RAM 162 comprises a history information storage unit 162 a which stores the history information of players that was read from the server device 3 at the start of the game, and the game progress information of oneself and all opponents obtained via the network communication unit 18, which is progress information during the versus game of the same table (same game space) that is obtained successively for each player, a game score storage unit 162 b which stores, for each player, the ranking (including points of point sticks as needed) as the game score of the players at the end of the game that was decided by the score processing unit 161 d, and an attribute storage unit 162 c which stores attributes such as the quantity of one's own items, dan grade or title that were read from the server device 3 at the start of the game.

FIG. 5 is a hardware configuration diagram showing one embodiment of the server device 3. The control unit 36 controls the overall operation of the server device 3, and comprises an information processing unit (CPU) 361, a RAM 362 for temporarily storing personal information of the respective players, game score information of the respective players, and fraud information of the respective players, and a ROM 363 which stores in advance predetermined image information for management, management programs, ranking processing programs and the like.

Data that can be stored in a removable recording medium among the various types of data stored in the ROM 363 may also be readable with drivers of, for example, a hard disk drive, an optical disk drive, a flexible disk drive, a silicon disk drive, a cassette medium reader or the like. In the foregoing case, the recording medium is, for example, a hard disk, an optical disk, a flexible disk, a CD, a DVD, a semiconductor memory or the like.

The network communication unit 38 sends and receives various types of information and data to and from the corresponding game terminal devices 1 according to the terminal identification information through one among the plurality of routers 2 via a network configured from WWW or the like.

Note that the management programs are recorded in the ROM 363, and the respective functions are realized by the management programs being loaded into the RAM 362 and such management programs in the RAM 362 being sequentially executed by the CPU 361.

FIG. 6 is a functional configuration diagram of the control unit 36 of the server device 3. As a result of executing the game management programs retained in the RAM 362, the CPU 361 of the control unit 36 functions as an acceptance unit 3611 which executes the sequential entry management processing in response to the game entries by the players using the respective game terminal devices 1, an allocation unit 3612 which allocates, in principle, the entrant players to a virtual table according to the rules described later, a fraud determination unit 3613 which determines whether player whose entry was accepted by the acceptance unit 3611 is a suspected fraud player who is suspected of committing fraudulent acts, and a restriction unit 3617 which imposes predetermined restrictions on the allocation of that player when the entrant player is determined to be a suspected fraud player. The fraud determination unit 3613 comprises a log acquisition processing unit 3614, a short-term fraud countermeasure processing unit 3615, and a long-term fraud countermeasure processing unit 3616. Moreover, the CPU 361 comprises an internal timer (clock means) that is generated by conventional software.

The RAM 362 comprises a player information storage unit 3620 which stores personal information such as the user ID, a score storage unit 3621 which stores, in an updating manner, the game score (win/loss record) for each player, and an attribute storage unit 3622 which stores, in an updating manner, attributes such as the dan grade and title for each player. Moreover, the RAM 362 includes a log storage unit 3623 which stores information for performing the determination processing in the fraud determination unit 3613. The log storage unit 3623 comprises a partnering frequency information storage unit 3624, a partnering history information storage unit 3625, a partnering restricted list storage unit 3626, a partnering prohibition list storage unit 3627, a joint discard processing list storage unit 3628, and a player list storage unit 3629.

Moreover, The RAM 362 comprises a ranking information storage unit (not shown) which stores, in an updating manner, the score and ranking information of all players that are successively calculated by a ranking calculation unit or the like not shown within the CPU 361 of the control unit 36. The updated ranking information is automatically, or based on request, distributed to the respective game terminal devices 1 by the communication control unit 3618 and displayed on the monitor 11.

The partnering frequency information storage unit 3624 stores accumulated information within a predetermined long period concerning all two-player teams (A and B) that played a match at the same table, and information of the total partnering count and frequency parameter according to the team of reference ID (A) and reference ID (B). The reference ID (A) and the reference ID (B) are the user IDs of player A and player B. The total partnering count is the total number of times that the players were partnered (played at the same table), and the frequency parameter is a parameter showing the frequency of partnering (for example, number of times/hour). A long period is, for example, several days to roughly one week.

The partnering history information storage unit 3625 stores information of a short period; for instance, for one day, concerning all two-player team (A and B) that played a match at the same table, and information of the partnering count corresponding to the team of reference ID (A) and reference ID (B).

The partnering restricted list storage unit 3626 stores the reference ID as information concerning the suspected fraud player who is acknowledged as engaging in joint discard.

The partnering prohibition list storage unit 3627 stores the reference ID (A) and the reference ID (B) of the team of the two suspected fraud players who are acknowledged as engaging in joint discard.

The joint discard processing list storage unit 3628 obtains information concerning the joint discard processing by using information from the partnering frequency information storage unit 3624.

The player list storage unit 3629 obtains the reference ID with at least a joint discard history, and information concerning the frequency parameter total.

The log acquisition processing unit 3614 reads the log information stored in the RAM 362 as needed and uses it for the fraud determination processing.

The short-term fraud countermeasure processing unit 3615 monitors the two-player team from the log information of a versus game during a short period; for example, during one day, and determines whether that team needs to be registered in a partnering prohibition list from the partnering conditions.

The long-term fraud countermeasure processing unit 3616 monitors the status of joint discard from the log information of each player during a predetermined long period (several days to roughly one week), and performs processing of registering the team of players, who were determined to be partnering restricted players, in the partnering prohibition list when such players are allocated to the same table after the foregoing determination.

The acceptance unit 3611 accepts entries to the game upon receiving the player's personal information such as the user ID sent from the game terminal device 1 and the identification information of the game terminal device 1. In addition, a password or other authentication processing may be added. Moreover, the acceptance unit 3611 commands the allocation unit 3612 to perform the allocation processing for the grouping of the opponents when the player is designating an entry to a versus game.

The allocation unit 3612 executes the grouping processing (partnering) of the opponents so that four players are allocated to a virtually prepared table, for example, in the order of entry to the acceptance unit 3611. When the four players to play at the table are decided, the allocation unit 3612 reads the player's player information including the user ID from the player information storage unit 3620, and distributes this to the corresponding game terminal device 1. Note that the method of selecting the opponents is not limited to the order of entry, and the grouping may also be decided by giving consideration to one or more attributes of the player contained in the player information such as the dan grade or title, ranking, near or far of the installation site of the game terminal devices, and so on.

FIG. 7 is an example of the screen view of the mahjong game match screen. The game screen sets a match screen area 500 is a main area. The match screen area 500 displays the tile hand 501 of the player at the lower side of the screen so that the type of tile is visible, displays the tile hand 502 of the opponents at the upper and left and right sides off the screen so that the type of tile is not visible, displays a mountain 503 including the dora tile and discarded tiles 504 around the mountain 503 at the approximate center of the screen, and displays various buttons 506 to be pressed by the player at the lower side of the screen. The game is advanced by the player pressing the appropriate buttons 506 while viewing the match screen 500.

Incidentally, a fraudulent act of two players simultaneously performing game entry operations in collusion so as to be allocated to the same table, and one player sacrifices oneself; that is, plays the role of a loser, and thereby allows the other team player to play the game advantageously (play the role of a winner). For example, although the screen of a mahjong game does not show the type of tile of opponent players other than oneself as shown in FIG. 7, by communicating with one's team player or playing the game using adjacent game terminal devices 1, it is possible to engage in fraudulent joint discard of discharging the type of tile that will enable the player playing the role of a winner to win via pon or the like for each tsumo. The fraud determination unit 3613 and the restriction unit 3617 prevent such fraud player team from being allocated to the same table.

FIGS. 8 to 11 are flowcharts explaining the processing of advancing the mahjong game to be executed by the CPU 361 of the server device 3. FIG. 8 is a flowchart showing the processing in the case of receiving a signal from the game terminal device 1. FIG. 9 is a flowchart showing the processing in the case where the received signal was an acceptance signal. FIG. 10 is a flowchart showing the processing in the case where the received signal was game end. FIG. 11 is a flowchart showing the suspected fraud player extraction processing to be executed every predetermined short period (one day).

In FIG. 8, interruption is permitted (step S1), and whether a signal was received is determined (step S3). If a signal has not been received, the routine exits the flow. If a signal has been received, processing according to the type of received signal is performed (step S5). Here, acceptance processing (FIG. 9) and game end processing (FIG. 10) are taken as examples, but the other types of processing are also performed in a similar manner.

In FIG. 9, if the received signal is determined to be an acceptance signal, the player and the game terminal device 1 are identified from the user ID and the like and the identification information of the game terminal device 1 included in the received signal, specific information is sent to the allocation unit 3612, and the allocation unit 3612 decides the table of the player; that is, decides the grouping with the other opponent players (step S11). Once the grouping is decided, the required information such as the player information and log information of the four players included in the grouping is sent, together with a game start command signal, to the respective game terminal devices 1 to play the mahjong game at the same table (step S13).

In FIG. 10, if the received signal is determined to be a game end signal, the log information including the game score information of the player included in the received signal is acquired, and updated (step S21). Subsequently, as needed, the ranking processing is performed (step S23). Note that the ranking processing can also be performed immediately before the ranking display that is performed according to the player's request or each time upon reaching a predetermined time.

In FIG. 11, an internal timer or the like is referred to in order to determine whether a predetermined period (for example, one day) has elapsed (step S31), and the flow is ended if such predetermined period has lapsed. If it is determined that the predetermined period has not lapsed, the short-term fraud countermeasure processing (step S33) and the long-term fraud countermeasure processing (step S35) are performed, and the flow is ended.

FIG. 12 and FIG. 13 are flowcharts showing the allocation processing (step S11) that is executed by the CPU 361 of the server device 3, FIG. 14 is a flowchart showing the short-term fraud countermeasure processing (step S33), and FIG. 15 to FIG. 18 are flowcharts showing the long-term fraud countermeasure processing (step S35).

Foremost, the reference ID and the attribute information such as the dan grade and title as information of the game entrant player, and the score of the last game are received (step S41). Subsequently, whether there is a table in waiting is determined (step S43). If there is no table in waiting, a new table is created, information of that player is registered in, or allocated to, that table (step S45), and the routine returns to step S41.

Meanwhile, if there is a table in waiting, the player's score of the last game is compared with the scores of the last game of the members of that table (other players who have already been allocated to that table) (step S47). This comparison processing is the determination processing for preventing joint discard, as much as possible, by referring to the scores of the last games of the two players regardless of whether they were playing a match at the same table in the last game. This is performed, for example, as follows. A winning role threshold WP and a losing role threshold LP are let in advance. Then, if the score of the last game of the target player is P and the score of the last game of the previously allocated player is Pn (n indicates the player who has already been allocated, so it will be P1 if the player was allocated first and will be P2 is the player was allocated second), T=1 if P>=WP, T=−1 if P<=LP, and T=0 if LP<P<WP. Moreover, Tn=1 if Pn>=WP, Tn=−1 if Pn<=LP, and Tn=0 if LP<Pn<WP. In the foregoing cases, if T×Tn>=0 regarding all players under the current conditions, it is determined as appropriate (Yes in step S47), and determined as inappropriate if not (No in step S47). If the result is inappropriate, allocation of the player to that table is restricted, moved to the next table, and appropriate is determined (step S49 to step S43). Note that this may also be determined based on the existence of a relationship of first place and fourth place in substitute for the high or low of scores.

If the determination is appropriate in step S47, whether the grouping of the respective members of that table is registered in the partnering prohibition list is determined (step S51). This determination is the determination processing of preventing joint discharge by referring to the partnering record based on the partnering count or frequency of the two-player team. This is performed, for example, as follows. If the reference ID of the target player is R and the reference ID of the previously allocated player is Rn, it is determined as appropriate (appropriate in step S51) when R≠reference ID (A) and Rn≠reference ID (B), and Rn≠reference ID (A) and R≠reference ID (B) relative to the reference ID (A) and the reference ID (B) of players of a certain team in the partnering prohibition list, and determined as inappropriate if not (inappropriate in step S51). If the result is inappropriate, the routine proceeds to searching for the next table (step S49 to step S43).

Meanwhile, if it is determined as appropriate in step S51, the processing of allocating the target player to that table is performed; that is, information of the player is registered in (allocated to) that table (step S53).

Subsequently, whether the head-count limit of players to be allocated to the table (four people in this embodiment) has been reached or whether the cut-off time has been reached is determined (step S55). When this determination is denied, the routine returns to step S41. Note that the determination may be affirmed upon reaching the head-count limit.

Meanwhile, if the determination in step S55 is affirmed, processing for the subsequent determination is performed. Specifically, the determination of whether a player registered in the partnering restricted list is included in the members of that table is made according to the determination rules described later (step S57). If there is no player who is registered in the partnering restricted list, the partnering contents in step S55 are registered as log information. The table allocation processing of the next game entrant player is thereafter repeated.

Meanwhile, if there is a player who is registered in the partnering restricted list, the grouping of that partnering restricted player and the other players is registered in the partnering prohibition list (step S59), and the routine proceeds to step S61.

FIG. 14 is a flowchart showing an example of the short-term fraud countermeasure processing. Foremost, the partnering history information as the log information of the previous day is read from the top (step S71). Note that this read processing is for monitoring the log information of one day in the past in this embodiment, and this processing is assumed to be performed at the end of the business day or at the start of the following business day.

In the reading from the first row, whether there is partnering history information regarding the grouping of the two-player team is determined (step S73). If there is no partnering history information, the routine exits this flow. Meanwhile, if there is partnering history information, whether the partnering count of the team of the reference ID (A) and the reference ID (B) exceeds a threshold N is determined (step S75). The value N is the threshold for determining joint discard. If the partnering count of the team of the reference ID (A) and the reference ID (B) exceeds the threshold N, that team is registered in the partnering prohibition list (step S77). Contrarily, if the partnering count of the team of the reference ID (A) and the reference ID (B) is less than the threshold N, the routine skips step S77 and proceeds to step S79. In step S79, the partnering history information of the next team is read, and routine returns to step S73, and the monitoring of all partnering history information is performed.

FIG. 15 to FIG. 18 are flowcharts showing an example of the long-term fraud countermeasure processing. Foremost, on a daily basis, data of the joint discard processing list and the player list are cleared (emptied), and the partnering frequency information is read (step S81). Subsequently, the frequency parameter in the read partnering frequency information is decremented by one across the board (step S83). This is to lessen the frequency for the lapse of each day. Subsequently, the partnering history information of the previous days is read from the first row (step S85). Then, the existence of partnering history information is determined (step S87). If there is partnering information, whether the same information as this partnering frequency information; that is, whether there is a team with the same reference ID (A) and the reference ID (B) is determined (step S89). If there is no same team, partnering frequency information is newly registered (step S91). In the newly registered partnering frequency information, the frequency parameter is set to Pi, and the total partnering count is set to the partnering count. Note that the value Pi is the initial frequency parameter value that becomes the basis upon determining joint discard.

Meanwhile, if there is a same team in step S89, the partnering frequency information is rewritten (step S93). Specifically, the frequency parameter is updated to partnering count+Pb, and the total partnering count is updated to the partnering count. Note that the value Pb is a frequency parameter penalty value capable of determining joint discard. The partnering frequency information of the next row is thereafter read (step S95), and the routine returns to step S87.

Meanwhile, if all partnering history information is read and it is determined that there is no partnering history information in step S87, the partnering frequency information in which the frequency parameter value is 0 or less is deleted among the partnering frequency information (step S97). Next, the partnering frequency information is read from the first row (step S99). Then, the existence of the partnering frequency information is determined (step S101). If there is partnering frequency information, whether the frequency parameter value of the partnering frequency information is greater than A1 is determined (step S103). The value A1 is a determination threshold for determining the existence of joint discard. If the frequency parameter value of the partnering frequency information is greater than A1, this partnering frequency information is added to the joint discard processing list (step S103). The partnering frequency information of the next row is thereafter read (step S107), and the routine returns to step S101.

Meanwhile, if the frequency parameter value of the partnering frequency information is less than A1, the routine skips step S105 and proceeds to step S107.

Moreover, if there is no partnering frequency information in step S101, the joint discard processing list is read from the first row (step S109), and the existence of the joint discard processing list is determined (step S111). If there is a joint discard processing list, whether the reference ID (A) is registered in the player list is subsequently determined from the joint discard processing list (step S113). If the reference ID (A) is registered in the player list, information of the reference ID (A) of the player list is rewritten (step S115), and the routine proceeds to step S119. For the rewriting of the reference ID (A) of the player list, the frequency parameter of the joint discard processing list is written into the frequency parameter total column. Meanwhile, if the reference ID (A) is not registered in the player list, the player of the reference ID (A) is newly registered in the player list, and the frequency parameter of the joint discard processing list is written into the frequency parameter total column of the reference ID (A) of the newly registered player list (step S117), and the routine proceeds to step S119.

In step S119, whether the reference ID (B) is registered in the player list is subsequently determined. If the reference ID (B) is registered in the player list, information of the reference ID (B) of the player list is rewritten (step S121), and the routine proceeds to step S125. For the rewriting of the reference ID (B) of the player list, the frequency parameter of the joint discard processing list is written into the frequency parameter total column. Meanwhile, if the reference ID (B) is not registered in the player list, the player of the reference ID (B) is newly registered in the player list, and the frequency parameter of the joint discard processing list is written into the frequency parameter total column of the reference ID (B) of the newly registered player list (step S123), and the routine proceeds to step S125. Subsequently, in step S125, the joint discard processing list of the next row is read, and the routine returns to step S111.

Meanwhile, in step S111, if there is no joint discard processing list, the player list is read from the first row (step S127), and the existence of the player list is determined (step S129). If there is a player list, whether the frequency parameter total of that player list is greater than A2 is determined (step S131). The value A2 is the determination threshold capable of acknowledging that a certain player is playing the role of a winner as the main culprit of the fraudulent joint discard.

If the frequency parameter total is greater than A2, that player is registered in the partnering restricted list (step S133). The player list of the next row is subsequently read (step S135), and the routine returns to step S129. Meanwhile, if the frequency parameter total is less than A2, the routine skips step S133 and proceeds to step S135.

Note that the present invention can also adopt the following modes.

(1) Although the present invention was explained as a mahjong game as an example of a versus game, it is not limited thereto, and the present invention can be applied to various types of versus games that are played by at least three or more players.

(2) In this embodiment, the reference ID (A) and the reference ID (B) were registered in the partnering history information only based on partnering/non-partnering, but alternatively, the reference ID (A) and the reference ID (B) can also be registered when the game win/loss record of the reference ID (A) and the reference ID (B) is first place and fourth place. It is thereby possible to increase the surveillance accuracy of joint discard.

(3) In this embodiment, the partnering count of the partnering history information and the frequency parameter of the partnering frequency information were calculated only based on partnering/non-partnering, but alternately, weighting may be added according to the cases where the ranking of the reference ID (A) and the reference ID (B) is first place and fourth place, first place and third place, and first place and second place in order to more accurately determine the possibility of joint discard. Moreover, a case of second place and fourth place can also be included. In other words, it is possible to include a level where one player can be acknowledged as playing the role of a winner and the other player can be acknowledged as playing the role of a loser.

(4) In this embodiment, the allocation unit 3612, the log acquisition processing unit 3614, the fraud determination unit 3613, and the restriction unit 3617 were provided to the server device 3, but it is also possible to provide a part or all of such units to the game terminal device 1.

As explained above, the present invention is a game system comprising respective game terminals which allow a plurality of players to play a versus game in a same game space via a network, and a game server which is provided on the network and which manages the players who participate in the versus game, wherein the game terminal has acceptance means for accepting entries to the versus game, and the game server has: allocation means for allocating players, whose entry has been accepted, to the game space according to predetermined rules;

log storage means for storing, as log information, game scores of the respective players, and other players who played a versus game in a same game space every time the game ends; fraud determination means for performing first fraud determination processing of determining, based on a record of allocation to the same game space of a team of two players who have been allocated to the same game space which is obtained from the log information, whether those two players are suspected fraud players committing joint discard, and registering in a partnering prohibition list the team of the two players when those two players are determined to be suspected fraud players, and second fraud determination processing of determining, based on a record of allocation to the same game space of each player in relation to a plurality of other players which is obtained from the log information, whether that player is a suspected fraud player committing joint discard, and registering in the partnering prohibition list teams of that fraud player and each of the other players allocated to the same game space when that player is determined to be a suspected fraud player; and restriction means for restricting the allocation of two players to the same game space when those two players whose entries to the versus game have been accepted are registered as a team of suspected fraud players in the partnering prohibition list.

Accordingly, the collaborators who are suspected of committing fraud are not allocated to the same game space based on the first fraud determination processing with an immediate effect, and the suspected fraud player to play the role of the winner is extracted and that player and the suspected fraud collaborator are not allocated to the same game space based on the second fraud determination processing with a delayed effect, and fraudulent acts are thereby inhibited effectively.

Moreover, preferably, the acceptance means comprises a reading unit for reading identification information on a player from a recording medium recorded with the identification information on that player. According to the foregoing configuration, since the acceptance of entries to the game is performed by reading the information stored in the recording medium, even in cases where a plurality of types of recording mediums are prepared, allocation to the same game space is inhibited with a delayed effect based on the second fraud determination processing.

Moreover, preferably, the allocation means allocates a predetermined number of players to the same game space according to the order of entry acceptance. According to the foregoing configuration, the fraud entrants who engage in simultaneous entry can be effectively allocated to different game spaces.

Moreover, preferably, the first fraud determination processing determines a team of two players to be suspected fraud players when the number of times that the two players have been allocated to the same game space during a predetermined period exceeds a predetermined threshold. According to the foregoing configuration, by setting, as the predetermined threshold, a situation where the number of times that players are allocated to the same game space is probabilistically impossible (numerous) during a predetermined period, during one day for instance, when determined according to the total number of players, the two-player fraud team that will engage in joint discard can be extracted more quickly.

Moreover, preferably, the second fraud determination processing determines a team of players to be suspected fraud players when an allocation frequency according to the record of allocation of a certain player and the plurality of other players to the same game space exceeds a predetermined threshold. According to the foregoing configuration, by monitoring the allocation record of a certain player with the other plurality of players, even in cases where one player is impersonating the other plurality of players, the two-player fraud team that will engage in joint discard can be extracted effectively.

Moreover, preferably, the restriction means restricts the allocation of two players to the same game space upon determining that a win/loss record of the last versus game of each of those two players whose entries to the versus game have been accepted shows that one of those players was a winner and the other one of those players was a loser. According to the foregoing configuration, when the win/loss record of the last match of both players was one player playing the role of a winner and the other player playing the role of a loser regardless of whether it was the same game space, both players are not allocated to the same game space. Thus, it is possible to immediately allocate players who are likely to engage in fraud to different game spaces, and thereby prevent fraud.

Moreover, preferably, the fraud determination means reads the log information daily and updates registration information of the partnering prohibition list. According to the foregoing configuration, the restriction processing can be performed easily since the team of fraud players is ultimately extracted, in an updated manner, only based on the partnering prohibition list.

EXPLANATION OF REFERENCE NUMERALS

-   1 game terminal device -   2 router -   3 server device -   4 card reader -   161 CPU -   161 a acceptance processing unit -   161 b game progress control unit -   161 d score processing unit -   162 RAM -   361 CPU -   3611 acceptance unit -   3612 allocation unit -   3613 fraud determination unit -   3614 log acquisition processing unit -   3615 short-term fraud countermeasure processing unit -   3616 long-term fraud countermeasure processing unit -   3620 player information storage unit -   3621 score storage unit -   3623 log storage unit -   3624 partnering frequency information storage unit -   3625 partnering history information storage unit -   3626 partnering restricted list storage unit -   3627 partnering prohibition list storage unit -   3628 joint discard processing list storage unit -   3629 player list storage unit 

1. A game system comprising respective game terminals which allow a plurality of players to play a versus game in a same game space via a network, and a game server which is provided on the network and which manages the players who participate in the versus game, wherein the game terminal has acceptance means for accepting entries to the versus game, and the game server has: allocation means for allocating players, whose entry has been accepted, to the game space according to predetermined rules; log storage means for storing, as log information, game scores of the respective players, and other players who played a versus game in a same game space every time the game ends; fraud determination means for performing: first fraud determination processing of determining, based on a record of allocation to the same game space of a team of two players who have been allocated to the same game space which is obtained from the log information, whether those two players are suspected fraud players committing joint discard, and registering in a partnering prohibition list the team of the two players when those two players are determined to be suspected fraud players, and second fraud determination processing of determining, based on a record of allocation to the same game space of each player in relation to a plurality of other players which is obtained from the log information, whether that player is a suspected fraud player committing joint discard, and registering in the partnering prohibition list teams of that fraud player and each of the other players allocated to the same game space when that player is determined to be a suspected fraud player; and restriction means for restricting the allocation of two players to the same game space when those two players whose entries to the versus game have been accepted are registered as a team of suspected fraud players in the partnering prohibition list.
 2. The game system according to claim 1, wherein the acceptance means includes a reading unit for reading identification information on a player from a recording medium recorded with the identification information on that player.
 3. The game system according to claim 1, wherein the allocation means allocates a predetermined number of players to the same game space according to the order of entry acceptance.
 4. The game system according to claim 1, wherein the first fraud determination processing determines a team of two players to be suspected fraud players when the number of times that the two players have been allocated to the same game space during a predetermined period exceeds a predetermined threshold.
 5. The game system according to claim 1, wherein the second fraud determination processing determines a team of players to be suspected fraud players when an allocation frequency according to the record of allocation of a certain player and the plurality of other players to the same game space exceeds a predetermined threshold.
 6. The game system according to claim 1, wherein the restriction means restricts the allocation of two players to the same game space upon determining that a win/loss record of the last versus game of each of those two players whose entries to the versus game have been accepted shows that one of those players was a winner and the other one of those players was a loser.
 7. The game system according to claim 1, wherein the fraud determination means reads the log information daily and updates registration information of the partnering prohibition list.
 8. A game management method of a game server which manages players who play a versus game in a same game space by operating respective game terminals connected to a network, wherein allocation means allocating players, whose entry has been accepted, to the game space according to predetermined rules, log storage means storing, as log information, game scores of the respective players, and other players who have played a versus game in the same game space every time the game ends, fraud determination means performing first fraud determination processing of determining, based on a record of allocation to the same game space of a team of two players who have been allocated to the same game space which is obtained from the log information, whether those two players are suspected fraud players committing joint discard, and registering in a partnering prohibition list the team of the two players when those two players are determined to be suspected fraud players, and second fraud determination processing of determining, based on a record of allocation to the same game space of each player in relation to a plurality of other players which is obtained from the log information, whether that player is a suspected fraud player committing joint discard, and registering in the partnering prohibition list teams of that fraud player and each of the other players allocated to the same game space when that player is determined to be a suspected fraud player, and restriction means restricting the allocation of two players to the same game space when those two players whose entries to the versus game have been accepted are registered as a team of suspected fraud players in the partnering prohibition list.
 9. A game management program of a game server which manages players who play a versus game in a same game space by operating respective game terminals connected to a network, the game management program causing the game server to function as: allocation means for allocating players, whose entry has been accepted, to the game space according to predetermined rules; log storage means for storing, as log information, game scores of the respective players, and other players who have played a versus game in the same game space every time the game ends; fraud determination means for performing first fraud determination processing of determining, based on a record of allocation to the same game space of a team of two players who have been allocated to the same game space which is obtained from the log information, whether those two players are suspected fraud players committing joint discard, and registering in a partnering prohibition list the team of the two players when those two players are determined to be suspected fraud players, and second fraud determination processing of determining, based on a record of allocation to the same game space of each player in relation to a plurality of other players which is obtained from the log information, whether that player is a suspected fraud player committing joint discard, and registering in the partnering prohibition list teams of that fraud player and each of the other players allocated to the same game space when that player is determined to be a suspected fraud player; and restriction means for restricting the allocation of two players to the same game space when those two players whose entries to the versus game have been accepted are registered as a team of suspected fraud players in the partnering prohibition list.
 10. A game system comprising respective game terminals which allow a plurality of players to play a versus game in a same game space via a network, and a game server which is provided on the network and which manages the players who participate in the versus game, wherein the game terminal has acceptance means for accepting entries to the versus game, and wherein either the game terminal or the game server has: allocation means for allocating players, whose entry has been accepted, to the game space according to predetermined rules; log storage means for storing, as log information, game scores of the respective players, and other players who have played a versus game in the same game space every time the game ends; fraud determination means for performing first fraud determination processing of determining, based on a record of allocation to the same game space of a team of two players who have been allocated to the same game space which is obtained from the log information, whether those two players are suspected fraud players committing joint discard, and registering in a partnering prohibition list the team of the two players when those two players are determined to be suspected fraud players, and second fraud determination processing of determining, based on an allocation record to the same game space of each player in relation to a plurality of other players which is obtained from the log information, whether that player is a suspected fraud player committing joint discard, and registering in the partnering prohibition list teams of that fraud player and each of the other players allocated to the same game space when that player is determined to be a suspected fraud player; and restriction means for restricting the allocation of two players to the same game space when those two players whose entries to the versus game have been accepted are registered as a team of suspected fraud players in the partnering prohibition list. 